4,495 research outputs found
Design and initial testing of a one-bladed 30-meter-diameter rotor on the NASA/DOE mod-O wind turbine
The concept of a one-bladed horizontal-axis wind turbine has been of interest to wind turbine designers for many years. Many designs and economic analyses of one-bladed wind turbines have been undertaken by both United States and European wind energy groups. The analyses indicate significant economic advantages but at the same time, significant dynamic response concerns. In an effort to develop a broad data base on wind turbine design and operations, the NASA Wind Energy Project Office has tested a one-bladed rotor at the NASA/DOE Mod-O Wind Turbine Facility. This is the only known test on an intermediate-sized one-bladed rotor in the United States. The 15.2-meter-radius rotor consists of a tip-controlled blade and a counterweight assembly. A rigorous test series was conducted in the Fall of 1985 to collect data on rotor performance, drive train/generator dynamics, structural dynamics, and structural loads. This report includes background information on one-bladed rotor concepts, and Mod-O one-bladed rotor test configuration, supporting design analysis, the Mod-O one-blade rotor test plan, and preliminary test results
Contemporary American Drama: William Vaughn Moody and Eugene O\u27Neil
In any study of contemporary American drama, two names inevitably stand out from among the myriads of native playwrights - those names - William Vaughn Moody and Eugene O\u27Neil. Yet neither of these can be literary pigeon-holed. Moody\u27s death prevented him reaching his full development. Consequently his work is mostly indicative - indicative of what it might have been had he lived
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Making Implicit Methods Explicit: Trade Press Analysis in the Political Economy of Communication
The political economy of communication (PEC) situates media systems and practices in their structural and historical contexts; however, PEC scholars rarely articulate or justify their research methods. To address this oversight, this article explains how PEC scholars use trade publications to study media industries, practices, policy making, and discourses thereof. Following a critical realist approach, PEC researchers âburrow downâ in trade press advertisements and reports and âlisten inâ to the frank, insider discussions therein. This article evaluates the trade press against Scottâs four âquality control criteriaâ for documentary sourcesâauthenticity, credibility, representativeness, and meaning. Trade publications employ daunting industry jargon, and they can be cozy with the industries they cover. Still, the trade press provide otherwise unobtainable insights into the structure and organization of media industries, how they are regulated, and the practices and worldviews of media executives and professionals. This article argues that by approaching the trade press ethnographically, PEC researchers can reap their benefits while avoiding pitfalls
Semiclassical analysis of defect sine-Gordon theory
The classical sine-Gordon model is a two-dimensional integrable field theory,
with particle like solutions the so-called solitons. Using its integrability
one can define its quantum version without the process of canonical
quantization. This bootstrap method uses the fundamental propterties of the
model and its quantum features in order to restrict the structure of the
scattering matrix as far as possible. The classical model can be extended with
integrable discontinuities, purely transmitting jump-defects. Then the quantum
version of the extended model can be determined via the bootstrap method again.
But the outcoming quantum theory contains the so-called CDD uncertainity. The
aim of this article is to carry throw the semiclassical approximation in both
the classical and the quantum side of the defect sine-Gordon theory. The CDD
ambiguity can be restricted by comparing the two results. The relation between
the classical and quantum parameters as well as the resoncances appeared in the
spectrum are other objectives
The sine-Gordon model with integrable defects revisited
Application of our algebraic approach to Liouville integrable defects is
proposed for the sine-Gordon model. Integrability of the model is ensured by
the underlying classical r-matrix algebra. The first local integrals of motion
are identified together with the corresponding Lax pairs. Continuity conditions
imposed on the time components of the entailed Lax pairs give rise to the
sewing conditions on the defect point consistent with Liouville integrability.Comment: 24 pages Latex. Minor modifications, added comment
Free Field Realization of Vertex Operators for Level Two Modules of
Free field relization of vertex operators for lvel two modules of
is shown through the free field relization of the modules
given by Idzumi in Ref.[4,5]. We constructed types I and II vertex operators
when the spin of the addociated evaluation modules is 1/2 and typ II's for the
spin 1.Comment: 15 pages, to appear in J.Phys.A:Math and Genera
Using handheld pocket computers in a wireless telemedicine system
Objectives: To see if senior emergency nurse practitioners can provide support to
inexperienced ones in a Minor Injuries Unit by using a wireless LAN system of
telemedicine transmitting images to a PDA when they were on duty. In addition,
whether such a system could be sufficiently accurate to make clinical diagnoses with
a high level of diagnostic confidence. This would permit an overall lower grade of
nurse to be employed to manage most of the cases as they arrive with a proportionate
lowering of costs.
Methods: The wireless LAN equipment could roam in the Minor Injuries Unit and
the experienced emergency Nurse practitioners could be at home, shopping or even
at a considerable distance from the centre.
Thirty pictorial images of patients who had been sent to the Review Clinic were
transmitted to a PDA various distances of one to sixteen miles from the centre. Two
senior emergency nurse practitioners viewed the images and opined on the diagnosis,
their degree of confidence in the diagnosis and their opinion of the quality of the
image.
Results: the images of patients were sharp, clear, and of diagnostic quality. The
image quality was only uncertain, as was the level of confidence of the diagnosis if
the patient was very dark skinned.
Conclusions: The wireless LAN system works with a remote PDA in this clinical
situation. However there are question marks over the availability of enough
experienced emergency nurse practitioners to staff a service that provides senior
cover for longer parts of the day and at weekends
Performance and power regulation characteristics of two aileron-controlled rotors and a pitchable tip-controlled rotor on the Mod-O turbine
Tests were conducted on the DOE/NASA mod-0 horizontal axis wind turbine to compare and evaluate the performance and the power regulation characteristics of two aileron-controlled rotors and a pitchable tip-controlled rotor. The two aileron-controlled rotor configurations used 20 and 38 percent chord ailerons, while the tip-controlled rotor had a pitchable blade tip. The ability of the control surfaces to regulate power was determined by measuring the change in power caused by an incremental change in the deflection angle of the control surface. The data shows that the change in power per degree of deflection angle for the tip-controlled rotor was four times the corresponding value for the 2- percent chord ailerons. The root mean square power deviation about a power setpoint was highest for the 20 percent chord aileron, and lowest for the 38 percent chord aileron
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